Product: Dynamics Business Central 365 (BC365)
Article Link: http://help.truecommerce.com/en/articles/6433577-business-central-error-invalid-asn-type

The Invalid ASN Type means that you're attempting to import a Shipment/ASN from Business Central into Transaction Manager, but you haven't defined what type of ASN it is within the Shipment inside Business Central.
Without this, Transaction Manager won't know which type to use and as such cannot continue until this is set within Business Central
Quick Fix
Navigate: Shipment → Related → TrueCommerce
Set: TC ASN Type
Full Articles: Need a full breakdown or not sure which ASN Type to use? Read our ASN Types article for BC

rev 8/1/22